1. Field of the Invention
The present invention relates to a production managing system of semiconductor devices in which a production of semiconductor devices is managed by a remote user by using an information communication line such as an internet, etc.
2. Description of Related Art
The production management of semiconductor devices ordered by a user has been performed by a semiconductor device manufacturer by measuring parameters of the semiconductor devices in respective production process steps thereof along a production line and checking the measured parameters on whether or not the parameters are within predetermined specifications.
That is, for example, thickness of a thin film formed on a substrate is checked on whether or not its thickness is within a thickness specification thereof in the forming step of the thin film and a wiring pattern is checked on whether or not a width thereof is within a width specification of the wiring pattern in a wiring pattern forming step in which the wiring pattern is formed by etching the thin film through a photolithographic step.
However, a production management in these checks is to merely determine whether or not a result of check is acceptable.
Final yield of semiconductor device, that is, the number of semiconductor devices obtained finally as acceptable products, is confirmed by confirming electrical characteristics and operations of completed semiconductor devices, which are functionally acceptable, by using a semiconductor tester.
Therefore, it is usual that a user who ordered the semiconductor devices can not know the number of normal semiconductor devices, which are practically obtained, before the production of all of them is completed.
As mentioned above, since, in the conventional production management of semiconductor devices, it is impossible for the user to know the number of finally obtainable normal semiconductor devices in every process and to confirm the number of normal semiconductor devices having acceptable electric characteristics before the semiconductor devices are completed, the user can not know the number of normal products until the semiconductor devices are delivered to the user.
Therefore, if a result obtained in the check in every process can not be detected by usual check in the conventional production management, there may be a case where the number of completed products delivered to the user is smaller than the number of products ordered by the user.
Therefore, when the shortage of the number of normal products is confirmed after the number of normal products is confirmed, it is necessary for the user to throw in a lot (constituted with in unit of wafer or wafers) again for production of semiconductor devices the number of which corresponds to the shortage. However, the production of semiconductor devices of the newly thrown lot usually takes about two months from the throwing-in of the lot to a completion of the semiconductor devices. Therefore, in the case where the number of normal products is short due to abnormality of process, a production schedule thereof is delayed substantially.